[ltp] Internal speakers are on although stereo jack plugged

[Richard]

> Hi,
>
> when i plug the stereo jack in my dock, the internal speakers of my T43 don't  get mute.
> The internal speakers only mute when i plug directly into my laptop.
> Does anybody have a solution? Is this a problem with ALSA or with the hardware?
>

That sounds like a hardware design problem - but a rather understandable 
one. Normally, the insertion of the jack-plug breaks an electronic circuit 
to the speakers. But the jack-socket in the dock cannot have this sort of 
loopback connection - if it did, then removing the laptop from the dock 
would have the same effect (and the internal speakers would never work).

You might be out of luck here. Other options:

1)Try gnome-alsamixer (or amixer) to see whether you can do anything 
clever with permutations of the controls.

2)Insert a dummy jack plug into the headphone output on the laptop.

3)Use a USB soundcard. The Behringer one (sorry, can't recall the number) 
is $20, works perfectly with Linux, and avoids the problem of interference 
being coupled into your hifi. (I usually find that internal soundcards 
pick up interference from the motherboard psu, as the CPU switches in/out 
of sleep at 100Hz; thinkpads are much better than most, but it's still 
audible)

Regards,

Richard